The Highmont property is situated in the Stanford Range which is comprised of complexly faulted and folded clastic and carbonate rocks that range in age from Proterozoic to Middle Devonian. The north portion of the property is underlain by Ordovician dolomite. The southern area is underlain by Ordovician dolomite and Devonian evaporites. On the west, the Burnais fault forms the contact between Ordovician and Devonian sediments. On the east, Devonian evaporites unconformably overlie Ordovician dolomites.

Mineralization consists of galena, sphalerite and barite, hosted in dolomite breccia. The breccia structure is developed in dolomite along the Ordovician unconformity. Typical mineralization consists of dolomite clasts in a matrix of dolospar, barite, galena and sphalerite. The best showing is a lense-like structure 1.5 by 30 metres with a best grade of 7.4 per cent zinc and 0.27 per cent lead (Assessment Report 19368).